In an attempt to further increase circuit density and reduce costs, three-dimensional (3D) semiconductor package structures have been developed. With the evolving of semiconductor technologies, semiconductor devices are becoming increasingly smaller, while more functions need to be integrated into the semiconductor devices. Accordingly, the semiconductor devices need to have increasingly greater numbers of input/output (I/O) terminals packaged into smaller areas, and the density of the I/O terminals rises quickly with time. As a result, the packaging of the semiconductor devices becomes more difficult, which adversely affects the yield of the packaging.